Friday 8 October 2004 20.27 EDT
First published on Friday 8 October 2004 20.27 EDT

In the illustrations to Edith Nesbit's children's books, you see girls and boys trussed up in pinafores and petticoats, knickerbockers and tight jackets, but in the books themselves you meet children who are as individual as any Harry or Lyra from contemporary children's literature. It's a pity that the forthcoming film of Five Children and It doesn't manage to get the energy of the protagonists on to the screen. Instead, the director, John Stephenson, puts them into a box of period eccentricity, and there they stay.

That will feel like a real missed opportunity to those people who, despite the passage of 100-odd years since they were written, find something surprisingly alive in Nesbit's books. Perhaps they feel so alive because her style is still so influential on so many levels. Some critics have called her the first modern writer for children. This isn't quite true - the accolade surely belongs to Lewis Carroll - but her work is more obviously the progenitor of a tradition than his is. It is hard to see how we would have had the children's literature we do have in Britain, with its effective mixtures of realism and fantasy, if it hadn't been for the inspiration she kindled.

She wanted to give her children very direct voices, capable of expressing the ordinary human emotion that a writer as playful as Carroll tends to avoid. To do that she had to get beyond a tradition of Victorian flowery silliness about childhood. She herself had done hackwork that used such silliness, and was 40 before she tried something else. But in The Story of the Treasure Seekers she suddenly moved on to new ground, with a child's voice that can express emotion vividly: "Our mother is dead, and if you think we don't care about her because I don't tell you much about her you only show that you do not undertand people at all," Oswald Bastable remarks sharply on the second page.

Even when she started the vein of fantasy that defines her best work, Nesbit kept up this matter-of-fact tone. When four of the children in Five Children and It wish for wings, and get them, Nesbit keeps a lid on the possibility of floweriness. "Not so dusty," says the sand-fairy who grants the wish. And there is always a sensual precision to her language that makes the magic come very close to the reader. The wings give the children "a funny feeling, half heaviness and half lightness" on their shoulders. They were of "lovely mixed changing colours ... like the beautiful scum that sometimes floats on water and is not at all nice to drink".

There is something absolutely precise about such writing, as though she were describing not a charming fancy, but something she had seen herself and was determined to record accurately.

This trick of importing the patterns of realist literature into fantasy, rather than using the bland rhetoric of previous fantasy writers such as William Morris or George MacDonald, is what makes Nesbit feel so close to us. "It" himself, the sand-fairy, or psammead, with his mean temper and witty asides and peculiar looks, is part of that style - his character is drawn like a character in a realist novel, all contrasting angles rather than pretty effects. In contrast, look at how whimsically fairies were usually shown in literature at that time. MacDonald's Phantastes , a fairyland work of the previous generation, is full of sugary fancies such as "a little forest of wild hyacinths alive with exquisite creatures, who stood nearly motionless with drooping necks, holding each by the stem of her flower, and swaying gently with it".

Even stroppy little Tinkerbell, brought to life by JM Barrie two years after the psammead made his appearance, is called into being by pure sentiment: "When a new baby laughs for the first time a fairy is born," Barrie wrote. Such whimsy was completely alien to Nesbit's imagination.

The unsentimental precision about magic that she perfected characterises the best children's fantasies that come after her. She showed writers how to make magic worlds thick with detail, sensual and solid. CS Lewis knew her work well and happily borrowed from her tone, her devices, and her effects. In The Magician's Nephew , published 50 years after Five Children and It, a character from another world, Jadis, Queen of Charn, suddenly stumbles into London. She is followed by crowds of policemen and curious onlookers, to the horror of the children who feel responsible for her presence and for getting her away again. That scene echoes a moment in one of Nesbit's best books, The Story of the Amulet , when a queen from ancient Babylon comes unexpectedly into London to jeers from the crowds: "Ere's a guy!"

Both writers have fun exploring how embarrassingly out of place an eruption of magic would be in modern London. "Now I must go and see your King and Queen," says Nesbit's queen. "Nobody's allowed to," the children reply hopelessly. "Tomorrow I will begin the conquest of the world," says Lewis's. "I- I'll go and order a cab at once," replies the children's uncle.

JK Rowling's games with parallel worlds also have something of the Nesbit style. In The Story of the Amulet, the children step through their magic arch in various places, including Regent's Park.

"The opening of the arch was small ... all round and beyond it were the faded trees and trampled grass of Regent's Park, where the little ragged children were playing ring o'roses. But through the opening of it shone a blaze of blue and yellow and red. Cyril drew a long breath and stiffened his legs so that the others should not see that his knees were trembling and almost knocking together. 'Here goes!' he said, and stepping through the arch, disappeared."

Harry Potter too finds that London has unexpected fissures that open into other worlds, so that he can walk into a solid metal barrier on King's Cross and fall through to a brighter place. Indeed, the motif of everyday streets and parks and stations suddenly revealing gaps on to other places has become a foundation stone for this kind of fantasy literature. In The Subtle Knife, Philip Pullman creates a window hanging on a pavement, through which his hero, Will, suddenly sees a cat disappearing:

"It looked as if someone had cut a patch out of the air, about two metres from the edge of the road ... all you could see through it was exactly the same kind of thing that lay in front of it on this side: a patch of grass ... but Will knew without the slightest doubt that that patch of grass on the other side was in a different world."

This ability to show so physically how worlds could open on to one another is as effective in Nesbit's works as it is in those writers who benefited from her influence. In fact, in some ways, Nesbit, who was born in 1858 and lived until 1924, feels more edgy and disconcerting than many contemporary writers of fantasy for children. This is because she is, essentially, ironic. Despite her fabulous inventions - the phoenixes that come with a flying carpet, the amulets that grow and provide a passage to other times, the statues that walk, the rings that confer invisibility - Nesbit's narratives as a whole tend to be a catalogue of disappointments and confusions. Magic promises everything, but turns out to be a source of chaos.

This gives her work a very different flavour from many of those who seem to working under her influence. In the tales of Lewis or Rowling or Pullman the children find themselves part of a grand quest, a huge cosmic battle in which they will play a destined role. In Nesbit's work everything is much more anarchic, and the children are always unsure whether they are going to be thrown into the darkest dungeon in Egypt or be sent to bed without supper. For her, magic worlds are as chaotic as real life; there are no Voldemorts or Dumbledores, no forces of pure evil or pure good, in her fantasies. So the children have to muddle through just as they would in everyday life.

Perhaps this shows that, in a reversal of what we might expect, she is a writer who refuses to idealise childhood, while some of those who came after her wanted to idealise it to an extreme. The children in Nesbit's books keep being reminded that there is nothing very special about them at all. In The Story of the Amulet, when they find the sand-fairy again and he tells them how to find a magic charm, he reminds them stiffly, "You're still very ignorant, and rather silly, and I am worth a thousand of you any day of the week." This is very far from the huge bloating wind of destiny that hovers behind the heroes of Rowling's or Lewis's fantasies.

The lack of any simplistic moralism is what makes her work hard to adapt for film now. Oddly for a writer who is seen as such a purveyor of charm and magic, she does not provide enough escapism for current tastes. It's not suprising that the writers for the forthcoming film of Five Children and It add a quest to the story, in which the children are searching for their father, who is a pilot in the first world war. This is reminiscent of Nesbit's most sentimental children's book, The Railway Children, which spawned the only successful film made of her work.

But even in The Railway Children, it is the realism that gives the book its edge. The mother of the children, sweet and wonderful as she is, is also a good portrait of the writer as sole breadwinner for a family. "Whenever an Editor was sensible, there were buns for tea." That feels real enough, because it was real enough; the woman who imagined such light fancies as enchanted rings and sand fairies had to keep hard at her writing for her living. If her work moves sometimes joltingly from realism to fantasy, that was because that was her life - she was a romantic who had to spin those fancies to pay the bills.

She knew what it was to be forced to be independent - to be thrown back on one's own emotional and financial resources. But she also knew what it was to demand independence, and try to live an authentic life in defiance of convention, so that Noël Coward judged her "the most genuine Bohemian I had ever seen". Although Nesbit never called herself a feminist and even disapproved of the suffragette cause (though usually she explained this with the argument that socialist politics would only be advanced by full adult suffrage rather than the limited householder enfranchisement that was being advanced by many suffragettes), she was a woman who struggled constantly against traditional expectations.

Her biographers, Doris Langley Moore and Julia Briggs, have charted that struggle for readers - Moore in the way considered suitable for readers of the first half of the 20th century, and Briggs more frankly.

What comes through, though often obscure and contradictory, is solidly admirable. It is clear that Nesbit could have gone under very early on, when as a romantic teenager she fell for Hubert Bland, then a penniless bank clerk with intellectual ambitions. They had both lack of money and socialist politics in common, yet they married when she was 22 and seven months pregnant. By the age of 28 she had three children and shared the marital home with one of Hubert's mistresses and her child, but together they all clambered upwards. The clambering came on the back of Hubert's career in political journalism - he became well known as a columnist and they were founder members of the Fabian Society. Then Edith began to tap her real talent. She had worked hard for years on poetry, grown-up novels and journalism, but it was only when her imagination found its voice in children's books, that the world - including HG Wells and Rudyard Kipling - assured her that what she was doing was unique. But to the end she was disappointed that it was as a children's author, a less respected path than now, rather than as a real poet, that she had found her audience.

She never stopped struggling for security; although her children's books were successful, they were all written under pressure as serials for magazines, against deadlines and bills piling up. Absolute security eluded her, and she died in relative poverty. Absolute romance eluded her too, as her husband took mistresses and her own love affairs - including a particularly unsatisfactory one with that supreme egoist George Bernard Shaw - failed to release her into the happy ending she craved.

No wonder her novels wander between dreams and the sharper end of reality. Even The Enchanted Castle , her most sustained and lovely achievement, and also one of her most sentimental works - with its subplot of a romance in which the magic wishing ring will finally be transformed into a wedding ring - dips back constantly into something more ironic. At the end the magic is put away with surprising finality.

"The suddenness with which all the ring-magic was undone was such a shock to everyone concerned that they now almost doubt that any magic ever happened." That jolt is typical of her endings, which throw the reader suddenly back into the real world, feeling rather comfortless - except for the fact that something brighter did appear, and because your guide to that brightness seemed so sure and down to earth, for a while you believed that you could trust her.